Zootaxa 1882: 46–56 (2008) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ ZOOTAXA Copyright © 2008 · Magnolia Press ISSN 1175-5334 (online edition)

A new species of the pandalid shrimp genus Pandalus (Crustacea: Decapoda: Caridea) from the Sea of Okhotsk off eastern Sakhalin, Russian Far East

TOMOYUKI KOMAI1 & MARIA ELETSKAYA2 1Natural History Museum and Institute, Chiba, 955-2 Aoba-cho, Chuo-ku, Chiba, 260-8682 Japan. E-mail: [email protected] 2All-Russian Research Institute of Fisheries and Oceanography (VNIRO), Moscow, 107140, Russia. E-mail: [email protected]

Abstract

A new species of the pandalid shrimp genus Pandalus Leach, 1814, Pandalus ivanovi n. sp., is described on the basis of material from the Sea of Okhotsk off eastern Sakhalin, at depths of 150–200 m. It is morphologically closest to Pandalus hypsinotus Brandt, 1851, a commercially important species widely distributed in the northern North Pacific. Because of the strong similarities between the new species and P. hypsinotus, we have examined syntypes of the latter species in order to confirm the specific identity. The new species can be distinguished from P. hypsinotus by the more strongly upturned rostrum, the relatively low postrostral ridge on the carapace, fewer carpal articles of the left second pereopod and the small body size. The coloration in life is also different between the two. There is an indication of protandry in the new species, like other congeneric species.

Introduction

The pandalid shrimp genus Pandalus Leach, 1814 contains several species of particular interest for commer- cial fishery (Holthuis, 1980). Komai (1999) revised the taxonomy of the genus. He classified 19 species, including three new species described at that time, in four informal species groups (P. montagui group, P. stenolepis group, P. hypsinotus group, and P. platyceros group), and transferred Pandalus propinqvus G. O. Sars, 1869 to a new monotypic genus Atlantopandalus Komai, 1999. All Pandalus species are distributed in the northern hemisphere, and highest species richness is seen in the northwestern Pacific, where 12 species occur (Komai, 1999). Recently, many specimens representing a species of Pandalus, fished for commercial purpose in the Sea of Okhotsk off eastern Sakhalin, Far Eastern Russia, were sent to the first author for identification by Mr. S. Miyaki of Daiei-Taigen Co., Ltd., Japan. The shrimp from eastern Sakhalin is very similar to a pandalid spe- cies currently referred to Pandalus hypsinotus Brandt, 1851 in the morphology, but is clearly distinct from the latter species in several minor morphological differences and the coloration in life. Through exchange of information between the senior author and the late Dr. Boris G. Ivanov of the All-Russian Research Institute of Fisheries and Oceanography, Moscow (VNIRO), we realized that we were independently studying the same species. Finally, the authors decided to carry out a joint study on the Pandalus shrimp from eastern Sakhalin. Because of the close similarity between the two taxa, we have examined the syntypes of Pandalus hypsinotus in the collection of the Zoological Institute, St. Petersburg, in order to confirm the specific identity. As a result, the eastern Sakhalin shrimp was revealed undescribed, and in this paper, we describe a new spe- cies, Pandalus ivanovi, for this taxon.

46 Accepted by J. Goy: 26 Aug. 2008; published: 22 Sept. 2008